SUMMARYOPIUM WAS widely used in the nineteenth century as an analgesic, a febrifuge, a sedative, and an anti-diarrhoea agent. Opium's addictive properties had been noted in the medical literature as early as 1700, but medical men did not take these very seriously. With the advent of the hypodermic syringe in 1856, which made it possible for morphia (the alkaloid of opium) to be injected, physicians became increasingly concerned about addiction. From 1878, they began to discuss the "disease" of drug addiction. What had begun as a trickle in the medical literature eventually became a torrent and, by 1910, a fully mature disease model of drug addiction had been developed. This had an enormous influence on both the popular understanding and national policies toward drug addiction in the period between 1910 and 1930. The reasons why medical men characterized drug addiction as a disease derived from specific features ofthe "culture ofmedicine" in the late nineteenth century: the concept ofdisease, the social role and status of the medical profession, the perception ofpublic health concerns, and the political goals and influence of medical men. Considered within the context ofthe historiography ofmedicine, the development ofthe concept of drug addiction can illuminate how traditional and radical perspectives can be combined to produce a richer understanding of medical history.We intend to show how the disease model of drug addiction came to prominence in Britain in the late nineteenth century, and how this affected both popular understanding and national policy toward the issue.I have myself been in the habit of taking morphia for thirty years. I began by taking chlorodyne for a spasmodic complaint, as ordered by two eminent medical men. It was changed by my husband for morphia, with the result that by constantly increasing the dose it came at last to 4 scruples per week, which has been the regular quantity taken now for very many years.This medicine -so deleterious in most instances -has by no means impaired the vitality of my system, or tended in any degree to reduce my activity, which is equal to that ofmany young women, although I am now 67 years of age.My enjoyment of life is perfect, and I have none ofthe haggard, emaciated look borne by most persons who adopt this treatment. My eyes are black and bright, the sight being no worse than that of most persons my age.The only evil which appears to arise from the use ofthis medicine is a considerable increase offat, and I should be considerably obliged ifany ofyour contributors will kindly inform me ifthis increase ofadipose tissue is a natural result of the morphia.